Flat device and intake system

ABSTRACT

A valve device for an intake system of an internal combustion engine may include a housing and a flap arrangement. The housing may have one inlet duct per cylinder of the internal combustion engine. The flap arrangement may have a flap for each inlet duct for varying the cross-section of the respective inlet duct through which a flow can pass. The respective flap may be a trough-shaped flap having a curved stirrup region. The respective flap may be arranged between the stirrup ends eccentrically with respect to a flap pivot axis. The flap arrangement may have a common actuating shaft for the common pivoting of the flaps about the flap pivot axis. The actuating shaft may be coupled with an adjusting drive via a lever element having a metallic insert and a plastic body injected onto the insert.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application 10 2009054 184.5 filed on Nov. 23, 2009 and PCT/EP2010/06773 filed on Nov. 18,2010, which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a flap device for an intake system ofan internal combustion engine, in particular of a motor vehicle, withthe features of the introductory clause of claim 1. The invention alsorelates to an intake system equipped with such a flap device.

BACKGROUND

A flap device of the type named in the introduction is known from DE 19946 861 A1. The flap device has a housing which has precisely one inletduct for each cylinder of the internal combustion engine. In addition,the flap device has a flap arrangement which has for each inlet duct aflap for varying the cross-section of the respective inlet duct throughwhich a flow can pass.

In the known flap device, all the flaps together form an integral bodyin a single piece, which undertakes at the same time the function of theactuating shaft. The individual flaps in this flap device are configuredas butterfly flaps, which are arranged centrally with respect to theflap pivot axis.

From EP 0 726 388 A1 another flap device is known, in which the housingfor each cylinder of the internal combustion engine has two inlet ducts,wherein the flap arrangement has a flap for varying the cross-sectionthrough which a flow can pass only for every other inlet duct. For theactuation of the flaps, a common actuating shaft is provided, on whichthe individual flaps are arranged. For this, the actuating shaft has foreach flap a projection on which the respective flap is arranged, wherebya favourable torque transmission is produced between the actuating shaftand the flap.

In the known flap device, the flaps can be configured as butterfly flapsarranged centrally with respect to the flap pivot axis or as flapsformed eccentrically with respect to the flap pivot axis, projectingfrom the integral actuating shaft.

SUMMARY

The present invention is concerned with the problem of indicating for aflap device of the type named in the introduction or respectively for anintake system equipped therewith an improved or at least a differentembodiment, which is distinguished in particular in that the flaparrangement operates with a comparatively high precision, wherein inaddition the manufacturing costs are to be comparatively low.Alternatively or additionally, in the open position of the respectiveflap the influence on the air flow is to be reduced.

This problem is solved according to the invention by the subjects of theindependent claims. Advantageous embodiments are the subject of thedependent claims.

The invention is based on the general idea of designing the flaps astrough-shaped flaps, which are characterized by a curved stirrup regionand a shell region projecting therefrom, wherein for actuation of allthe flaps a common actuating shaft is provided, which has for each flapa projection which is situated in the stirrup region in the case of therespective flap. The use of a common actuating shaft on which theindividual flaps are arranged makes possible the use of differentmaterials for the actuating shaft on the one hand and the flaps on theother hand. In particular, the flaps can be injection-moulded fromplastic, whilst the actuating shaft can be produced from metal. Hereby,a secure and reliable actuation of the flaps can be realized.Injection-moulded parts can be produced with close tolerances, wherebythe flap device can operate with a comparatively high precision. Themetallic actuating shaft can be cast or forged or can also be producedin a particularly simple manner by deformation of a wire. The actuatingshaft is preferably designed as a single-piece, continuous shaft, intowhich the projections for the flaps are formed. The flaps can beproduced so that they can be clippable onto the actuating shaft;alternatively, it is also possible to inject the flaps directly onto theactuating shaft. The type of construction with flaps injected onto thecommon actuating shaft has the advantage that dimensional deviations dueto tolerance, which can occur in the production of the actuating shaft,can be eliminated during the injecting-on of the flaps. Thereby, theflap device has a very small misalignment. Furthermore, this compositecomponent can be produced at a particularly favourable cost.

In an advantageous further development of the invention, the flaps canbe arranged in cascades on the actuating shaft. Here, the flaps arefixed on the actuating shaft, being are rotated with respect to eachother by a few degrees (e.g. less than 10° or less than 5°). Thearrangement of the flaps is selected such that the flap which isarranged furthest away from the drive of the actuating shaft in theinstalled state comes to abut as the first one. The flap arrangednearest to the drive comes to abut as the last one. The remaining flapsare arranged with their angle of inclination accordingly between thesetwo flaps. Through this further development, it is ensured that all theflaps come to abut reliably against the intake manifold and each flaphas approximately the same pre-stressing. This has the advantage thattorsional vibrations are prevented and the intake manifold has improvedacoustic characteristics. The arrangement of the flaps on the actuatingshaft, or respectively the angle of inclination which is to be provided,is dependent on the torsion characteristics of the actuating shaft. Inthe case of more rigid shafts, smaller angles of inclination arenecessary than in the case of more flexible shafts.

According to an advantageous embodiment, the flaps and the inlet ductscan be coordinated with each other so that the respective flap extendsin its open position with its stirrup region and with its shell regionalong an inner wall of the respective inlet duct. Through this type ofconstruction, the flap in its open position, in which it is thereforenot required, is largely moved laterally out from the cross-section ofthe respective inlet duct through which a flow can pass. Hereby, theinfluence of the opened flap on the through-flow of the inlet duct canbe reduced.

According to an advantageous further development, the respective inletduct can have on its inner wall a depression into which the flap atleast partially dips in its open position at least with a section lyingbetween the stirrup ends. Through this provision, the influence of theopened and not required flap on the flow conditions in the inlet ductcan be again reduced.

A further reduction of the flow influence of the opened flap can berealized according to a further development in that the flap in its openposition terminates flush with the inner wall on the inflow side withits section dipping into the depression. Through this provision, thecontour of the flap which is exposed to the flow adjoins the contour ofthe inner wall of the inlet duct, which reduces the influence of theopened flap on the through-flow of the inlet duct.

According to another advantageous embodiment, the shell region of therespective flap can be adapted in the open position of the flap to thecontour of the inner wall. This provision also contributes to a furtherreduction of the interaction between the opened flap and the flow in theinlet duct.

According to an advantageous further development, the adaptation of theflap to the contour of the inner wall can be realized such that theshell region extends the contour of the inner wall in the flowdirection. In this way, the opened flap does not form a flow obstructionin the shell region, whereby the interaction with the movement of air inthe inlet duct is again reduced.

According to another advantageous embodiment, the respective shellregion can be configured asymmetrically. Hereby it can be achieved inparticular that the flap in its closed position within the associatedinlet duct realizes sections with cross-sections of different sizethrough which a flow can pass. By targeted configuration of theasymmetry it is possible, furthermore, to generate a swirl flow or atumble flow in the closed position of the respective flap. A furtherdevelopment is particularly advantageous here in which a first sectionof the shell region in a closed position of the respective flap comes toabut against a wall of the inlet duct, whilst a second section of theshell region in the closed position of the respective flap is spacedapart from the wall. This can be utilized for generating a defined inletflow into the respective cylinder.

Further important features and advantages of the invention will emergefrom the subclaims, from the drawings and from the associated figuredescription with the aid of the drawings.

It shall be understood that the features mentioned above and to beexplained in further detail below are able to be used not only in therespectively indicated combination, but also in other combinations or inisolation, without departing from the scope of the present invention.

Preferred example embodiments of the invention are illustrated in thedrawings and are explained in further detail in the followingdescription, wherein identical reference numbers refer to identical orsimilar or functionally identical components.

BRIEF DESCRIPTION OF THE DRAWINGS

There are shown, respectively diagrammatically

FIG. 1 a perspective, exploded view of a flap device,

FIG. 2 a side view of a flap arrangement in accordance with a viewingdirection II in FIG. 3,

FIG. 3 a side view of the flap arrangement in a viewing direction IIIaccording to FIGS. 2 and 4,

FIG. 4 a side view of the flap arrangement in a viewing direction IVaccording to FIG. 3,

FIG. 5 a sectional view of the flap device in the region of an inletduct,

FIG. 6 a sectional view as in FIG. 5, but with a different flapposition,

FIG. 7 a perspective view of a lever element,

FIG. 8 a perspective view of an insert of the lever element,

FIG. 9 a side view of the insert, but in a different embodiment,

FIG. 10 a perspective view in the region of a coupling between anactuating shaft and a rotation angle sensor,

FIG. 11 a perspective view of a housing of the flap device in the regionof a front face with the rotation angle sensor, but in a differentembodiment,

FIG. 12 a highly simplified sectional view of the flap device in theregion of a coupling between the flap arrangement and the rotation anglesensor,

FIG. 13 a perspective view of an intake system with the flap device,

FIG. 14 a sectional view of the flap device in an alternative design ofthe sensor region,

FIG. 15 a top view onto the flap device in the sensor region accordingto FIG. 14.

DETAILED DESCRIPTION

In accordance with FIGS. 1 to 15, an intake system 1, which can only beseen in FIG. 13, comprises a flap device 2 for connection to an internalcombustion engine, not shown here, which can be arranged in particularin a motor vehicle. The intake system 1 serves for the supply of air ofthe internal combustion engine, which is configured as a piston engineand has several cylinders. In the example which is shown, the intakesystem 1 has in addition a fresh air distributor 3, which has severalinlet pipes 4. In the embodiments shown here, the flap device 2 isdesigned as an intermediate flap, which in the mounted state is arrangedbetween the fresh air distributor 3 and the internal combustion engine.In particular, the flap device 2 can form a completely pre-mountableunit, which is able to be pre-mounted independently of the remainingintake system 1. In other embodiments, the intake system 1 can beembodied as a single-piece component, in which the function of theintermediate flange is integrated and the flap device 2 is introduceddirectly into a housing of the intake system 1.

According to other embodiments, the intermediate flange can also beconnected with other air supply units, such as e.g. compressors or airdistributors with or without a cooler, and can form an intake system.

In accordance with FIGS. 1 to 15, the flap device 2 comprises a housing5, which has precisely one inlet duct 6 per cylinder of the internalcombustion engine. In the example which is shown, the housing 5 isequipped with four inlet ducts 6. The flap device 2 can therefore beconfigured for an in-line four cylinder engine or else for a bank of aV-8 cylinder engine. The cylinder number or respectively the number ofinlet ducts 6 is, however, purely by way of example here.

In particular embodiments, the duct in the intake manifold can besingle-flow, i.e. an individual duct can be provided per cylinder. Inother embodiments, two ducts can be provided per cylinder; the duct istherefore embodied as a double-flow duct. The continuation of thesingle-flow or double-flow duct in the intermediate flange can likewisebe configured so as to be single-flow or double-flow. In thecylinder-head itself, the duct can likewise be embodied so as to besingle-flow or double-flow. Here, the number of ducts in thecylinder-head is dependent on the number of valves. Through thedifferent combination of single-flow or respectively double-flow ductsarranged one after the other, particular flows, such as e.g. swirl flowsand/or tumble flows, can be generated, which enable an optimum fillingof the cylinders.

The flap device 2 comprises in addition a flap arrangement 7. This has asingle flap 8 for each inlet duct 6. The flaps 8 serve to vary thecross-section of the respective inlet duct 6 through which a flow canpass. In accordance with FIGS. 1 to 6, the flaps 8 are designed here astrough-shaped flaps. Such a trough-shaped flap 8 is characterized on theone hand by a curved stirrup region 9 and on the other hand by a shellregion 10 projecting from the stirrup region 9. The respective stirrupregion 9 has two stirrup ends 11 spaced apart from each other, which arearranged respectively coaxially with respect to a flap pivot axis 12.The stirrup region 9 projects out from the flap pivot axis 12 betweenthe stirrup ends 11. Through these projections, the respective flap 8 isarranged between the stirrup ends 11 eccentrically with respect to theflap pivot axis 12.

The flap arrangement 7 has for all flaps 8 a common actuating shaft 8,by means of which the flaps 8 can be pivoted jointly about the flappivot axis 12. For each flap 8, the actuating shaft 13 has a projection14 with respect to the flap pivot axis 12. In the region of theseprojections 14, the actuating shaft 13 therefore runs eccentrically withrespect to the flap pivot axis 12. The individual flaps 8 are nowarranged in the region of the projections 8 on the actuating shaft 13.The arrangement of the flaps 8 on the actuating shaft 13 takes placehere expediently so that the respective flap 8 is arranged with itsstirrup region 9 along the respective projection 14. In accordance withFIGS. 5 and 6, the flaps 8 and the inlet ducts 6 can be expedientlycoordinated with each other so that the respective flap 8, in an openposition shown in FIG. 6, extends with its stirrup region 9 and with itsshell region 10 along an inner wall 15 of the respective inlet duct 6.The respective flap 8 can extend here such that or respectively soclosely along the inner wall 15 that a flowing around the flap betweenthe inner wall 15 and the shell region 10 is not possible or is largelyruled out.

In the embodiments shown here, the inlet duct 6 is equipped on its innerwall 15 with a depression 16. The latter is dimensioned and positionedso that the flap 8, in its open position, at least partially dips intothis depression 16 with a section lying between the stirrup ends 11. Theembodiment shown here is particularly advantageous in which the flaps 8and the inlet ducts 6 and the depressions 16 are coordinated with eachother so that the flap 8, in its open position according to FIG. 6,terminates flush with the inner wall 15 on the inflow side with itssection 17 dipping into the depression 16. In FIGS. 5 and 6 a flowdirection 18 is indicated by an arrow, in which the inlet duct 6 guidesthe fresh air to the associated cylinder. As can be seen, the flap 8terminates flush with the inner wall 15 on the inflow side in the regionof the depression 16.

It can also be seen from FIG. 6 that the shell region 10, in thepreferred embodiment shown here, is adapted in the open position to thecontour of the inner wall 15, and namely preferably such that the shellregion 10 extends the contour of the inner wall 15 in the flow direction18. Hereby, a low-resistance transition is created between the innerwall 15 and the flap 8, whereby it is possible to guide the fresh airflow in the open position to the respective cylinder, largely withoutinteraction with the flap 8.

The individual flaps 8 can basically be produced independently of theactuating shaft 13. They can be clipped onto the actuating shaft 13 orconnected with the actuating shaft 13 in another manner. However, anembodiment is preferred in which the flaps 8 are injected onto theactuating shaft 13. Here, the actuating shaft 13 is preferably made frommetal, whereas the flaps 8 are injection-moulded from plastic. Oninjecting the flaps 8 onto the actuating shaft 13, for examplemanufacturing tolerances of the actuating shaft 13 can be compensated.

As can be seen in particular from FIGS. 1, 5 and 6, the flaps 8 can beinjected onto the actuating shaft 13 so that the actuating shaft 13 inthe region of its projection 14 is only partially surrounded by the flapmaterial. Likewise, a full injecting around of the projections 14 by thematerial of the flap 8 is conceivable, for example in order to achieve aparticularly high-quality adaptation of the flap 8 or respectively ofthe shell region 10 to the contour of the inner wall 15.

In accordance with FIGS. 1 to 4, the actuating shaft 13 can have astraight bearing region 19 on both sides of each flap 8. Expediently,common bearing regions 19 are provided here between adjacent flaps 8. Inaccordance with FIGS. 1, 5 and 6, the housing 5 has several bearings 20.In these bearings 20, the bearing regions 19 of the actuating shaft 13are pivotably arranged about the flap pivot axis 12. These bearings 20can preferably be realized here in that respectively a first bearinghalf shell 21 is integrally formed on the housing 5, whilst a secondbearing half shell 22 complementary thereto is formed integrally on abearing part 23, which is mounted in a suitable manner onto the housing5. For example, these bearing parts 23 are inserted into correspondingbearing part mounts 24 which are constructed on the housing 5. By thefastening of the housing 5 on the internal combustion engine,automatically a sufficient fixing of the bearing parts 23 on the housing5 is then brought about. Likewise, it is possible to glue and/or jam thebearing parts 23 with the housing 5, i.e. to fix them by friction fit orforce fit.

FIG. 7 shows a lever element 28, by means of which the actuating shaft13 can be coupled with an adjusting drive 42 which can be seen in FIG.13. The adjusting drive 42 introduces a torque here into the leverelement 28 with respect to the flap pivot axis 12, wherein the leverelement 28 transfers this torque to the actuating shaft 13.

The embodiment which is shown here is particularly advantageous in whichthe lever element 28 has a metallic insert 29 and a body 30 of plastic,which is injected onto the insert 29. In the example of FIG. 7, theinsert 29 projects with an actuating section 31 out from the plasticbody 30. In accordance with FIG. 10, the lever element 28 can cooperatewith this actuating section 31 with a rotation angle sensor 32, whichcan be designed in particular as a Hall sensor. The rotation anglesensor 32 can detect the relative rotation position of the actuatingshaft 13 and hence of the flap arrangement 7.

In the example of FIG. 7, the lever element 28 has a lever arm 33, whichcan be coupled for example via a ball head 34 with the adjusting drive42 for the introduction of torque. Matching this, the insert 29 has alever arm section 35, which extends inside the lever arm 33. The leverarm section 35 can have an angled end section 36, which extends insidethe ball head 34. Opposite the actuating section 31, the insert 29 has acoupling section 37 here, which projects with respect to the actuatingsection 31 over the plastic body 30 and which in accordance with FIG. 10projects into an end 38 of the actuating shaft 13, which is slotted forthis, in order to thus be able to transfer torque to the actuating shaft13. In FIG. 10, to better illustrate the function of the insert 29, theplastic body 30 of the lever element 28 is omitted. The slot forreceiving the coupling section 37 is designated by 49.

In accordance with FIG. 7 a circular-cylindrical bearing section 39 canbe formed on the plastic body 30, by means of which the lever element 28can be mounted on the housing 5 so as to be rotatable about the flappivot axis 12. For this, the housing 5 can be equipped with a bearingmount 40 formed in a complementary manner with respect to the bearingsection 39, which bearing mount can be arranged on the front face of thebearing housing 5. In the embodiment shown in FIG. 13, the said bearingmount 40 is concealed by an additional housing 41, in which the leverelement 28 is accommodated and in which the coupling with the adjustingdrive 42 takes place, which in FIG. 13 is designed, by way of example,as a pressure cell. The rotation angle sensor 32 is mounted onto thisadditional housing 41.

In contrast to FIG. 8, FIG. 9 shows a different embodiment for realizingsuch an insert 29, which differs from the insert according to FIG. 8 bya modified coupling section 37′ and by a double-folded section 48.Whereas in the embodiment shown in FIG. 8 the coupling section 37 isdesigned so as to be flat, in order to be able to engage according toFIG. 10 into the mounting slot 49 at the front end 38 of the actuatingshaft 13, the coupling section 37′ in the embodiment shown in FIG. 9 isdesigned as a multi-sided mount. In a complementary manner thereto, theend 38 of the actuating shaft 13 on the front face is formed as apolygon, for example as a square. The double-folded section 48 extendsthe lever arm section 35 beyond the coupling section 37′ and therebyimproves the torque introduction into the plastic body 30.

FIGS. 11 and 12 show a different embodiment, in which the actuatingshaft 13, represented outside the housing 5 for illustration in FIG. 11,carries a magnet carrier 43 in a rotatably fixed manner. The said magnetcarrier 43, in turn, carries a permanent magnet 44 in a rotatably fixedmanner. The magnet carrier 43 is arranged expediently at an end 38 ofthe actuating shaft 13 on the front face. In the mounted state, thepermanent magnet 44 cooperates in a contact-free manner with acorrespondingly configured rotation angle sensor 32, which again can bedesigned in particular as a Hall sensor. The embodiment presented hereis particularly advantageous, in which the housing 5 according to FIG.12 has a wall section 46 between the permanent magnet 44 and therotation angle sensor 32. In other words, the permanent magnet 44 isarranged in the interior of the housing 5, whilst the rotation anglesensor 32 is arranged externally on the housing 5. Hereby, no separatesealing of the housing 5 has to be provided in the region of therotation angle sensor 32. In addition, it can be seen from FIG. 12 thatthe magnet carrier 43 keeps the permanent magnet 44 spaced apart axiallyfrom the wall section 46 with respect to the flap pivot axis 12, so thata gap 47 is produced axially between the wall section 46 and the magnetcarrier 43 or respectively the permanent magnet 44.

In the example which is shown, the rotation angle sensor 32 is fastenedparticularly simply on the housing 5, namely by a clipping arrangement.For this, clip elements 45 on the housing side can be formed integrallyon the housing 5, whereby the fastening of the rotation angle sensor 32on the housing 5 is able to be realized in a comparatively favourablypriced manner.

In FIG. 14 an alternative embodiment of the sensor region is illustratedin section. FIG. 15 shows the sensor region according to FIG. 14,without sensor 32, in top view. In contrast to the sensor regionillustrated in FIG. 12, the wall section 46 has a wall aperture 48. Thiswall aperture 48 is arranged in the region of the detection range of thesensor 32. Through this wall aperture 48, no sealing separation existsbetween the shaft end with the permanent magnet 44 and the sensor 32.Through the arrangement of the wall aperture 48, the magnetic field ofthe magnet 44 is transferred directly to the sensor 32. Therefore,materials can be used for the housing 5 or respectively for the entireintake system 1, which are magnetically or respectively electricallyconductive, without the magnetic field being influenced. Preferably,electrically conductive plastics can be used. The wall aperture 48 canhave any desired geometries, such as e.g. round, oval, rectangular orsquare. In the present example embodiment, the wall aperture 48 isdesigned in a V shape, wherein the wall aperture 48 becomes larger inthe mould release direction. Therefore, a mould release slider can besimply drawn away upwards. Furthermore, in this embodiment the sensor 32is arranged in a sensor mount 49, which has a conically constructedreceiving space 50 and a sealing region 51. The wall aperture 48 isarranged in the region of the receiving space 50. The sealing region 51is designed such that a seal 52, which in this example embodiment isconfigured as an O-ring seal, forms a seal between the sensor mount 49and the sensor 32 and thus the interior of the inlet ducts 6 is sealedwith respect to the environment. The receiving space 50 has a smallercross-section than the sealing region 51. Therefore, a shoulder 53 isformed between the receiving space 50 and the sealing region 51. Thewall aperture 48 extends from this shoulder 53 in the direction of thereceiving space 50. Therefore, the wall aperture 48 is able to beremoved from the mould simply. In this example embodiment, cropped flaps8 according to FIGS. 2 to 4 are integrated into the inlet ducts 6. Inother embodiments, the arrangement may, however, also have a flap shaftembodied in a straight line and flaps arranged thereon, with or withoutprojection regions. Of course, different combinations of single-flow anddouble-flow ducts can also be provided, as described above.

1. A valve device for an intake system of an internal combustion engine,comprising: a housing having one inlet duct per cylinder of the internalcombustion engine, a flap arrangement having a flap for each inlet ductfor varying the cross-section of the respective inlet duct through whicha flow can pass, wherein the respective flap is a trough-shaped flaphaving a curved stirrup region and a shell region projecting therefrom,wherein the respective stirrup region has two stirrup ends spaced apartfrom each other and arranged coaxially with respect to the flap pivotaxis, wherein the respective flap is arranged between the stirrup endseccentrically with respect to the flap pivot axis, wherein the flaparrangement has a common actuating shaft for the common pivoting of theflaps about the flap pivot axis, wherein the actuating shaft has aprojection for each flap, wherein the respective flap is arranged withits stirrup region along the associated projection on the actuatingshaft, wherein the actuating shaft is coupled with an adjusting drivevia a lever element, and wherein the lever element has a metallic insertand a plastic body injected onto the insert.
 2. The valve deviceaccording to claim 1, wherein the flaps and the inlet ducts arecoordinated with each other so that the respective flap in its openposition extends with its stirrup region and with its shell region alongan inner wall of the respective inlet duct.
 3. The valve deviceaccording to claim 2, wherein the respective inlet duct defines on itsinner wall a depression in which the flap in its open position at leastpartially dips with a section lying between the stirrup ends, whereinthe flap in its open position terminates flush with the inner wall oninflow side with its section dipping into the depression.
 4. The valvedevice according to claim 2, wherein the shell region of the respectiveflap in the open position is adapted to the contour of the inner wall sothat the shell region extends the contour of the inner wall in the flowdirection.
 5. The valve device according to claim 1, wherein therespective flap is injected onto the actuating shaft.
 6. The valvedevice according to claim 1, wherein the actuating shaft has a straightbearing region on both sides of each flap, wherein the housing has aplurality of bearings, the bearing regions of the actuating shaft beingmounted therein, wherein each bearing has a first bearing half shellformed integrally on the housing and a second bearing half shell formedon a bearing part mounted onto the housing.
 7. The valve deviceaccording to claim 1, wherein the flap arrangement includes an adjustingdrive for driving the actuating shaft, each flap being positionedproximally with respect to the adjusting device; wherein adjacent flapsare arranged on the actuating shaft offset to each other with respect tothe flap pivot axis by an angular difference, the angular differenceincreases with an increasing distance between each flap and theadjusting drive, wherein the angular differences of the flaps arecoordinated with each other so that a flap positioned distally withrespect to an adjusting drive for driving the actuating shaft on atleast one of closing and opening of the flaps firstly comes to abutagainst a wall of the respective inlet duct and the other flapssucceeding in decreasing distances from the adjusting drive come to abutin succession against the respective wall of the respective inlet duct,and wherein the angular difference between adjacent flaps is at leastone of a maximum 10°, a maximum 5° and a maximum 2°.
 8. The valve deviceaccording to claim 1, wherein the insert projects out from the plasticbody and cooperates with a rotation angle sensor to detect a rotationposition of the flap arrangement.
 9. The valve device according to claim8, wherein the plastic body has a circular-cylindrical bearing sectionrotatably mounted about the flap pivot axis in a complementary bearingmount of the housing.
 10. The valve device according to claim 1, whereinthe actuating shaft carries a magnet carrier in a torque-proof mannerand the magnet carrier carries a permanent magnet which cooperates witha rotation angle sensor for detection of a rotation position of the flaparrangement, wherein the housing has a wall section between thepermanent magnet and the rotation angle sensor.
 11. The valve deviceaccording to claim 1, wherein the housing is an intermediate flange,which is able to be mounted between the internal combustion engine andthe remaining intake system.
 12. An intake system for the fresh airsupply of an internal combustion engine, comprising: at least one flapdevice having a housing and a flap arrangement, wherein the housing hasone inlet duct per cylinder of the internal combustion engine, whereinthe flap arrangement has a flap for each inlet duct for varying thecross-section of the respective inlet duct through which a flow canpass, wherein the respective flap is a trough-shaped flap having acurved stirrup region and a shell region projecting therefrom, whereinthe respective stirrup region has two stirrup ends spaced apart fromeach other and arranged coaxially with respect to the flap pivot axis,wherein the respective flap is arranged between the stirrup endseccentrically with respect to the flap pivot axis, wherein the flaparrangement has a common actuating shaft for the common pivoting of theflaps about the flap pivot axis, wherein the actuating shaft has aprojection for each flap, wherein the respective flap is arranged withits stirrup region along the associated projection on the actuatingshaft, wherein the actuating shaft is coupled with an adjusting drivevia a lever element, and wherein the lever element has a metallic insertand a plastic body injected onto the insert.
 13. The valve deviceaccording to claim 3, wherein the shell region of the respective flap inthe open position is adapted to the contour of the inner wall so thatthe shell region extends the contour of the inner wall in the flowdirection.
 14. The valve device according to claim 13, wherein therespective flap is injected onto the actuating shaft.
 15. The valvedevice according to claim 14, wherein the actuating shaft has a straightbearing region on both sides of each flap, wherein the housing has aplurality of bearings, the bearing regions of the actuating shaft beingmounted therein, wherein each bearing has a first bearing half shellformed integrally on the housing and a second bearing half shell formedon a bearing part mounted onto the housing.
 16. The valve deviceaccording to claim 15, wherein the flap arrangement includes anadjusting drive for driving the actuating shaft, each flap beingpositioned proximally with respect to the adjusting device; whereinadjacent flaps are arranged on the actuating shaft offset to each otherwith respect to the flap pivot axis by an angular difference, theangular difference increasing with an increasing distance between eachflap and the adjusting drive, wherein the angular differences of theflaps are coordinated with each other so that a flap positioned distallywith respect to an adjusting drive for driving the actuating shaft on atleast one of closing and opening of the flaps firstly comes to abutagainst a wall of the respective inlet duct and the other flapssucceeding in decreasing distances from the adjusting drive come to abutin succession against the respective wall of the respective inlet duct,and wherein the angular difference between adjacent flaps is at leastone of a maximum 10°, a maximum 5°, and a maximum 2°.
 17. The valvedevice according to claim 16, wherein the insert projects out from theplastic body and cooperates with a rotation angle sensor to detect arotation position of the flap arrangement.
 18. The valve deviceaccording to claim 17, wherein the plastic body has acircular-cylindrical bearing section rotatably mounted about the flappivot axis in a complementary bearing mount of the housing.
 19. Thevalve device according to claim 18, wherein the actuating shaft carriesa magnet carrier in a torque-proof manner and the magnet carrier carriesa permanent magnet which cooperates with a rotation angle sensor fordetection of a rotation position of the flap arrangement, wherein thehousing has a wall section between the permanent magnet and the rotationangle sensor.
 20. The valve device according to claim 15, wherein thehousing is an intermediate flange, which is able to be mounted betweenthe internal combustion engine and the remaining intake system.